1. Field of the Invention
The present invention relates to a secondary battery.
2. Description of the Related Art
A lithium ion secondary battery includes a core pack having a bare cell and a protection circuit module.
The bare cell includes a positive electrode plate, a negative electrode plate, and a separator, supplies electric power to external electronic devices, and is capable of being repeatedly charged and discharged. The protection circuit module protects the secondary battery from overcharge and overcurrent, and from lowering of performance due to overdischarge.